Servelt使用注解方式配置Filter过滤器

我们在Filter过滤器中完成字符编码的统一格式。
代码如下

package com.microblog.filter;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.annotation.WebServlet;
import java.io.IOException;
@WebFilter("/*")//注意这里千万别写错了，很多时候不注意就写成了@WebServlet("/*"),就会导致项目运行时出现404错误！！！！切记。。。。。
public class CharEncoding implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, 
    FilterChain filterChain) throws IOException, ServletException {
             servletRequest.setCharacterEncoding("utf-8");
             servletResponse.setCharacterEncoding("utf-8");
             filterChain.doFilter(servletRequest,servletResponse);
    }

    @Override
    public void destroy() {

    }
}